
const _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
function encode(e) {
  var t = "";
  var n, r, i, s, o, u, a;
  var f = 0;
  e = _utf8_encode(e);
  while (f < e.length) {
    n = e.charCodeAt(f++);
    r = e.charCodeAt(f++);
    i = e.charCodeAt(f++);
    s = n >> 2;
    o = (n & 3) << 4 | r >> 4;
    u = (r & 15) << 2 | i >> 6;
    a = i & 63;
    if (isNaN(r)) {
      u = a = 64
    } else if (isNaN(i)) {
      a = 64
    }
    t = t + _keyStr.charAt(s) + _keyStr.charAt(o) + _keyStr.charAt(u) + _keyStr.charAt(a)
  }
  return t
}
function decode(e) {
  var t = "";
  var n, r, i;
  var s, o, u, a;
  var f = 0;
  e = e.replace(/[^A-Za-z0-9+/=]/g, "");
  while (f < e.length) {
    s = _keyStr.indexOf(e.charAt(f++));
    o = _keyStr.indexOf(e.charAt(f++));
    u = _keyStr.indexOf(e.charAt(f++));
    a = _keyStr.indexOf(e.charAt(f++));
    n = s << 2 | o >> 4;
    r = (o & 15) << 4 | u >> 2;
    i = (u & 3) << 6 | a;
    t = t + String.fromCharCode(n);
    if (u != 64) {
      t = t + String.fromCharCode(r)
    }
    if (a != 64) {
      t = t + String.fromCharCode(i)
    }
  }
  t = _utf8_decode(t);
  return t
}
function _utf8_encode(e) {
  e = e.replace(/rn/g, "n");
  var t = "";
  for (var n = 0; n < e.length; n++) {
    var r = e.charCodeAt(n);
    if (r < 128) {
      t += String.fromCharCode(r)
    } else if (r > 127 && r < 2048) {
      t += String.fromCharCode(r >> 6 | 192);
      t += String.fromCharCode(r & 63 | 128)
    } else {
      t += String.fromCharCode(r >> 12 | 224);
      t += String.fromCharCode(r >> 6 & 63 | 128);
      t += String.fromCharCode(r & 63 | 128)
    }
  }
  return t
}
function _utf8_decode(e) {
  var t = "";
  var n = 0;
  var r  = 0;
  var c1 = 0;
  var c2 = 0;
  var c3 =0;
  while (n < e.length) {
    r = e.charCodeAt(n);
    if (r < 128) {
      t += String.fromCharCode(r);
      n++
    } else if (r > 191 && r < 224) {
      c2 = e.charCodeAt(n + 1);
      t += String.fromCharCode((r & 31) << 6 | c2 & 63);
      n += 2
    } else {
      c2 = e.charCodeAt(n + 1);
      c3 = e.charCodeAt(n + 2);
      t += String.fromCharCode((r & 15) << 12 | (c2 & 63) << 6 | c3 & 63);
      n += 3
    }
  }
  return t
}
module.exports = {
  encode: encode,
  decode: decode,
}
